1. Technical Field
The present invention relates to a liquid crystal device, a driving method thereof, and an electronic apparatus, and more specifically, to a liquid crystal device of an OCB (Optical Compensated Birefringence) mode.
2. Related Art
In the field of liquid crystal devices represented by, particularly, liquid crystal televisions, etc., OCB-mode liquid crystals device with rapid response speed for the purpose of the improvement in image quality of dynamic images has been highlighted in recent years. In the OCB mode, liquid crystal molecules in an initial state are in spray alignment in which the molecules are developed in a spray between two substrates, and liquid crystal molecules are required to be bent in the shape of a bow during display operation (bend alignment). This is for modulating transmittance according to the degree of bend of the bend alignment during display operation. Since liquid crystal assumes the spray alignment in its initial state during power cutoff in the case of the OCB-mode liquid crystal device, it requires a so-called initial transfer operation in which an aligned state of liquid crystal is transferred to the bend alignment during display operation from initial spray alignment by applying a voltage more than a threshold voltage in power-up to liquid crystal. Here, since poor display occurs or desired high-speed responsiveness cannot be obtained unless the initial transfer is sufficiently performed, the techniques disclosed in JP A-2002-328399 and JP A-2002-357808 have been suggested to solve these points.
In JP A-2002-328399 and JP A-2002-357808, voltages having polarities reverse to each other are applied to a pixel electrode and a pixel electrode (or a pixel electrode and wiring) adjacent to each other (dot inversion driving) to generate a horizontal electric field therebetween, thereby causing disclination liquid crystal. This facilitates generation of transfer nuclei in liquid crystal, allowing transfer to the bend alignment at high speed. Since this method uses right-and-left rotation of liquid crystal molecules by the horizontal electric field for generation of transfer nuclei, it is important to control the rotating direction of liquid crystal molecules. Thus, for example, in JP A-2002-357808, a horizontal electric field is generated between adjacent pixel electrodes, and the shape of pixel electrodes is contrived by providing a projection at the edges of the pixel electrodes to rotate the rotating direction.
However, it cannot still be said that the transfer to the bend alignment is at a sufficiently high speed only by applying voltages having reverse polarities between adjacent pixel electrodes likes for example, the dot inversion driving, but realization of the initial transfer indispensable to the OCB mode at higher speed are desired. Moreover, when the shape of pixel electrodes is changed like JP A-2002-357808, there is a possibility that defects, such as a decrease in numerical aperture or poor alignment of liquid crystal molecules, may occur. Particularly when the area of pixels becomes small, these problems will appear conspicuously.